What organization tortures the narrator in 'The Pit and the Pendulum'?

The narrator in The Pit and the Pendulum is tortured by the Spanish Inquisition.

Poe's unnamed narrator is arrested, tried by sinister judges, and condemned in a setting associated with the Spanish Inquisition. He awakens in a dark prison cell, where a concealed pit, a descending razor-edged pendulum, and heated moving walls turn his imprisonment into a sequence of carefully staged executions.

The story was first published in 1842 in the literary annual The Gift: A Christmas and New Year's Present for 1843. Its historical setting is connected loosely with the Peninsular War, when French forces fought in Spain, but Poe takes major dramatic liberties with the chronology and practices of the Inquisition.

The famous pendulum torture is not a reliably documented standard Inquisition device. Poe likely drew on accounts associated with Juan Antonio Llorente's history of the Spanish Inquisition, including a disputed report of pendulum-like torture. The story's ending arrives when French troops capture Toledo and rescue the prisoner.